Method for rounding container corners



Oct. 23, 1962 H. DUNHAM mamoo FOR ROUNDING CONTAINER CORNERS 2 Sheets-Sheet 1 Filed March 10, 1960 n f l o FIGS . v llxl l hnv INVENTOR. HOMER DUNHAM w|Lso-,LEw|s Mam ATTORNEYS Oct. 23, 1962 H. DUNHAM FOR ROUNDING CONTAINER CORNERS METHOD Filed March 10, 1960 2 Sheets-Sheet 2 [L/////// II \7 a a q- 8 Q u L f r w 9') (\l v g 8 N F) P) INVENTOR. HOMER DUNHAM lrhLson, LEWIS i M: RAE

ATTORNEYS ate Unte Stats 3,059,551 METHUD FGR RGUNDENG CGNTAWER CORNERS Homer Dunham, 22332 Ann Arbor Trail, Dearborn, Mich. Filed Mar. 10, 1960, Ser. No. 14,015 1 Claim. (Cl. 9336) drops, pills, lozenges, candy and the like. Such containers may be classified into two groups. One group may be termed hard-pack containers. The second group may be referred to as soft-pack containers and are usually made from relatively thin paper. This invention is concerned with hard-pack containers.

Such containers are designed to be carried in the pocket or purse. When so carried, the sharp corners cause accelerated wear of the clothing, particularly of shirt pockets and coat pockets. This is a result of the almost constant rubbing between the sharp corners and the fabric. This process may be aggravated by the exudation of the hardened glue used to hold the container together. Another problem with such containers is that the sharp corners can cause scratches and skin laceration, as for example when the person carrying the container falls down. Additionally, the sharp corners have an uncomfortable feel when held in the hand or otherwise touched. The appearance of such sharp corners may also be considered to be undesirable in some cases. Square corners present a severe and harsh appearance, which for some products is not esthetically appealing.

-It has long been recognized as desirable to produce such containers with rounded corners. The rounding of corners has not been standard practice because of the high cost involved in preforming, and also sometimes the necessity for the assembly of several parts in order to obtain a radius corner. In particular, the rounding of corners is desirable for hard-pack cigarette packages. The use of the hard-pack has been retarded for this product because of the disadvantage of the sharp corners. This is true even though such packages offer the advantage of reducing the crushing of cigarettes, protection against perspiration, loss of loose tobacco, and staining of clothing. The modern high speed packaging methods for small containers makes it uneconomical to round the corners by the conventional techniques requiring additional preforming and assembly steps.

It is, therefore, an object of this invention to provide a method for rounding the corners of pocket-size hardpack containers after the containers are produced in the normal manner with sharp corners.

Another object of the invention is to provide a method whereby such containers may be subjected to corner rounding either before or after filling and Wrapping has been accomplished.

A further object of the invention is to provide a cornerrounding process which eliminates special molding, preforming and assembly work.

Other objects of this invention will appear in the following description and appended claim, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings:

FIG. 1 is a perspective view showing one embodiment of the apparatus of the present invention in operative relationship to a container which has had one corner rounded;

FIG. 2 is a perspective View of a container which has had all eight corners rounded;

FIG. 3 is a top plan view of apparatus for rounding several corners of a container simultaneously;

FIG. 4 is a side elevational view of a conveyor system for containers with one embodiment of the apparatus of the present invention mounted in operative relationship thereto;

FIG. 5 is a view taken substantially along the lines 55 of FIG. 4 looking in the direction of the arrows.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various Ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

The method of this invention is adapted to the purpose of rounding the sharp corners of pocket-size containers. It comprises positioning at least one corner of the container adjacent a forming plate and striking and crushing the corner with the forming plate to cause rounding thereof.

The type of containers referred to are small, pocketsize hard-pack containers such as are used for cigarettes and the like. As shown in FIG. 2, the containers are in the shape of rectangular prisms having six sides and eight corners. For the purposes of this invention, the container may be manufactured from any crushable material, such as cardboard, hard paper, plastic, thin metal, or metal foil.

The practice of the invention involves a single step, and requires only the addition of simple apparatus to any high speed conveyor line Where the small packages are made, filled or wrapped. The process involves the slight crushing of the sharp, square, cubical corners by a hard plate.

As shown in FIG. 1, a container 10 is positioned with at least one corner 11 adjacent a forming plate 12. The forming plate 12 is carried on a plunger 14 of an electric solenoid 16. The solenoid 16 is mounted by means of bracket 18 to a supporting structure 20. The forming plate 12 is shown as having a concave striking surface 22. A concave surface is preferred as it produces a rounded corner having a nearly spherical shape. However, if desired, the surface may be convex or fiat.

In operation, power is applied to the solenoid, driving the plunger and forming plate towards the corner 11. When the plunger contacts the corner, it is driven a short distance further to crush the container material to cause the rounding illustrated in FIG. 1. Due to the geometry and mechanical properties of a cubical corner or pyramid, a momentary crushing force applied to the corner will cause the corner to collapse and assume a rounded shape. The rounding according to the present invention may not be a perfectly spherical segment. However, the appearance will seem rounded to casual observation, and structurally will ofier all of the advantages of a perfectly round corner.

Power to the solenoid 16 is applied through leads 17, 19. The power can be turned on and off by any standard switching arrangement. A switching circuit using low power control elements is desirable. The low power elements referred to are such as thyratron tubes, relays, silicon controlled rectifiers, and power transistors. While movement of the forming plate is shown as being accomplished by a solenoid, it will be appreciated that other means, actuated for example hydraulically, by air pressure, or mechanically, could be'used. The movement of the forming plate 12 towards the container may be pro-set, restricted mechanically, or restricted by the resistance of the container to produce the desired radius of curvature. The amountof crushing desired is usually less than one-half inch, generally from one-sixteenth to one-fourth of an inch. This radius provides a satisfactory curvature and prevents damage to the container or its contents.

Travel of the forming plate 12 is preferably along the axis of the pyramid-shaped corner. This results in a crushing action which is uniform about the corner to provide a spherical and symmetrical appearance. However, if desired, the forming plate may be moved in some other path to give a curvature other than spherical.

The embodiment shown in FIG. 3 illustrates the use of a plurality of forming plates to simultaneously round several corners of the container 1t). As there shown, a pair of solenoids 66, 68 are mounted adjacent two corners 70, 72. The solenoids are supported by brackets 74, 76 on support structure 78. As will be appreciated, two additional solenoids may be provided beneath the solenoids shown and four more solenoids may be mounted adjacent the opposite end of the container. This system is capable of rounding two, four or eight corners at the same time. A container that has had all eight corners rounded is illustrated in FIG. 2. A holding and positioning structure 24 is provided for the container 10 to position it with respect to the'forming plates and to hold it while the corners are being rounded.

FIG. 4 illustrates corner-rounding apparatus 44 mounted in operative relationship to a conveyor system of a packaging machine. Rollers 26, 28, having conveyor belts 30, 32, receive the containers 10 from a container-forming, filling, or wrapping stage. The containers pass over a guide roll 34 and into a spacing conveyor system which includes rollers 36, 38 and belts 40, 42. The belts 40, 42 are driven at a higher rate of speed than the belts 30, 32 whereby the containers 10 are spaced apart as shown. When the containers reach the corner-rounding apparatus 44 they are individually acted upon. The rollers 36, 38 may be driven by a slip clutch mechanism so that the conveyor belts 40, 42 maybe stopped momentarily as each container is being acted upon by the apparatus 44. Stopping of the conveyor and actuation of the apparatus 44 may be accomplished by a conventional control mechanism, such as a microswitch or photoelectric device. When the corners have been rounded, the containers pass over guide roll 35 and are received by belts 37, 39 which are driven by roller 41, 43.

The corner-rounding apparatus 44 is illustrated in FIG. 5. This apparatus is another embodiment of cornerrounding means capable of rounding all eight corners simultaneously. A pair of striking plates 46, 48 are positioned adjacent each end of the containerlO. These plates are each driven by a single solenoid structure 50, 52. The solenoids are mounted by means of brackets 54, 56 on support structures 58, 60. It will be appreciated that while in the structure 44, the forming plate is moved towards the container, relative motion could also be acwards the container.

The corner portions 62, 64 are preferably positioned at an angle of approximately forty-five degrees to the longitudinal plane of the container. This provides a crushing action which is uniform about the corner to result in a neat appearing package.

In the arrangement shown in FIG. 5, there is some sliding action at each area of contact with the container corner. To reduce friction, which decreases the distortion of the rounded corners, the striking surfaces can be lined with a material having a low coefiicient of friction, for example, tetrafluoroethylene plastic or the like.

The apparatus can be installed at any point on the conveyor line subsequent to the forming of the container. In some cases, the most logical point is directly after the filling operation, while in other instances, it may be after closing or wrapping of the container. The preferred positionment may be determined in each case. In the preferred procedure, all eight corners of the container are rounded at the same time. This may be accomplished by striking the corners as the container moves along the conveyor, or by stopping the conveyor momentarily to permit the rounding operation. When all eight corners are rounded at the same time, it is not usually necessary to hold the container in a special fixture.

As will be appreciated, the present invention permits rounding of container corners at a very low cost and as a rapid production technique which may be integrated into the standard packaging system. The resultant package has improved properties, both from the appearance and use standpoint.

Having thus described my invention, I claim:

A method for rounding the corners of pocket-size hardpack containers having the shape of rectangular prisms comprising providing a forming plate for each corner of the container, locating said forming plates around the exterior surface of a container, positioning the container to locate each cubical corner thereof adjacent a forming plate, simultaneously moving each forming plate along a path through the tip of its respective adjacent container corner, and simultaneously contacting and crushing each container corner with a forming plate to cause rounding of the corners.

References Cited in the file of this patent UNITED STATES PATENTS 276,797. Fowler May 1, 1883 2,411,622 Gayer Nov. 26, 1946 2,532,844 Hulbert et al. Dec. 5, 1950 2,673,496 Amberg et al Mar. 30, 1954 2,916,975 Gasior et a1 Dec. 15, 1959 

